If it were solely due to replenishment, no GPS III would need to be launched to this date.Plus they look kinda bad with Galileo operational with L5 and L1C in every satellite.
Quote from: macpacheco on 06/14/2021 06:38 pmIf it were solely due to replenishment, no GPS III would need to be launched to this date.Plus they look kinda bad with Galileo operational with L5 and L1C in every satellite.There have been a few problematic birds that were retired because of GPS III launches. There are several IIR SVs that are over 20 years old and well past their service lives as well.There’s been a hole at PRN 11 for a while that should be filled by GPS III soon.I agree that they need to get L5 and L1C operational, but that’s an OCX issue as well.
Quote from: Jansen on 06/14/2021 06:55 pmQuote from: macpacheco on 06/14/2021 06:38 pmIf it were solely due to replenishment, no GPS III would need to be launched to this date.Plus they look kinda bad with Galileo operational with L5 and L1C in every satellite.There have been a few problematic birds that were retired because of GPS III launches. There are several IIR SVs that are over 20 years old and well past their service lives as well.There’s been a hole at PRN 11 for a while that should be filled by GPS III soon.I agree that they need to get L5 and L1C operational, but that’s an OCX issue as well.PRN numbers aren't fixed, they are cycled. It's perfectly OK for one PRN to be free for months and months.I'm assuming this launch will use PRN11, before PRN11 is activated for GPS III SV06 another PRN will be retired, and when the next launch (or recomissioning happens) that PRN will be used again.Edit... It's not just ok, it's normal to always have one PRN unused. There are 32 PRN codes defined but there's a limit of 31 active GPS satellites (it's either an almanac or the ground control system limitation, I can't remember which). I don't ever recall seeing 32 active GPS PRNs.
Quote from: baldusi on 07/01/2021 02:17 amQuote from: macpacheco on 06/14/2021 08:44 pmQuote from: Jansen on 06/14/2021 06:55 pmQuote from: macpacheco on 06/14/2021 06:38 pmIf it were solely due to replenishment, no GPS III would need to be launched to this date.Plus they look kinda bad with Galileo operational with L5 and L1C in every satellite.There have been a few problematic birds that were retired because of GPS III launches. There are several IIR SVs that are over 20 years old and well past their service lives as well.There’s been a hole at PRN 11 for a while that should be filled by GPS III soon.I agree that they need to get L5 and L1C operational, but that’s an OCX issue as well.PRN numbers aren't fixed, they are cycled. It's perfectly OK for one PRN to be free for months and months.I'm assuming this launch will use PRN11, before PRN11 is activated for GPS III SV06 another PRN will be retired, and when the next launch (or recomissioning happens) that PRN will be used again.Edit... It's not just ok, it's normal to always have one PRN unused. There are 32 PRN codes defined but there's a limit of 31 active GPS satellites (it's either an almanac or the ground control system limitation, I can't remember which). I don't ever recall seeing 32 active GPS PRNs.Wasn't it that the 32nd PRN has to be used for ground support, or an Earth bound reference?Nope. PRNs from 1 to 63 have been defined for GPS satellite usage.https://www.gps.gov/technical/prn-codes/L1-CA-PRN-code-assignments-2020-Oct.pdfBut since there is currently a 31 active PRN limit, PRNs 1 through 32 are used with one always inactive. In the future it is hoped up to 36 active satellites will be possible (with a 6x6 constellation layout).Ground control segment doesn't use a PRN. PRNs are used to allow for the L1 C/A band to be shared between GPS, Galileo, Glonass, Compass, SBAS, ...Ground control segment talks to GPS satellites via dedicated frequencies.
Quote from: macpacheco on 06/14/2021 08:44 pmQuote from: Jansen on 06/14/2021 06:55 pmQuote from: macpacheco on 06/14/2021 06:38 pmIf it were solely due to replenishment, no GPS III would need to be launched to this date.Plus they look kinda bad with Galileo operational with L5 and L1C in every satellite.There have been a few problematic birds that were retired because of GPS III launches. There are several IIR SVs that are over 20 years old and well past their service lives as well.There’s been a hole at PRN 11 for a while that should be filled by GPS III soon.I agree that they need to get L5 and L1C operational, but that’s an OCX issue as well.PRN numbers aren't fixed, they are cycled. It's perfectly OK for one PRN to be free for months and months.I'm assuming this launch will use PRN11, before PRN11 is activated for GPS III SV06 another PRN will be retired, and when the next launch (or recomissioning happens) that PRN will be used again.Edit... It's not just ok, it's normal to always have one PRN unused. There are 32 PRN codes defined but there's a limit of 31 active GPS satellites (it's either an almanac or the ground control system limitation, I can't remember which). I don't ever recall seeing 32 active GPS PRNs.Wasn't it that the 32nd PRN has to be used for ground support, or an Earth bound reference?
Quote from: macpacheco on 07/01/2021 10:55 amQuote from: baldusi on 07/01/2021 02:17 amQuote from: macpacheco on 06/14/2021 08:44 pmQuote from: Jansen on 06/14/2021 06:55 pmQuote from: macpacheco on 06/14/2021 06:38 pmIf it were solely due to replenishment, no GPS III would need to be launched to this date.Plus they look kinda bad with Galileo operational with L5 and L1C in every satellite.There have been a few problematic birds that were retired because of GPS III launches. There are several IIR SVs that are over 20 years old and well past their service lives as well.There’s been a hole at PRN 11 for a while that should be filled by GPS III soon.I agree that they need to get L5 and L1C operational, but that’s an OCX issue as well.PRN numbers aren't fixed, they are cycled. It's perfectly OK for one PRN to be free for months and months.I'm assuming this launch will use PRN11, before PRN11 is activated for GPS III SV06 another PRN will be retired, and when the next launch (or recomissioning happens) that PRN will be used again.Edit... It's not just ok, it's normal to always have one PRN unused. There are 32 PRN codes defined but there's a limit of 31 active GPS satellites (it's either an almanac or the ground control system limitation, I can't remember which). I don't ever recall seeing 32 active GPS PRNs.Wasn't it that the 32nd PRN has to be used for ground support, or an Earth bound reference?Nope. PRNs from 1 to 63 have been defined for GPS satellite usage.https://www.gps.gov/technical/prn-codes/L1-CA-PRN-code-assignments-2020-Oct.pdfBut since there is currently a 31 active PRN limit, PRNs 1 through 32 are used with one always inactive. In the future it is hoped up to 36 active satellites will be possible (with a 6x6 constellation layout).Ground control segment doesn't use a PRN. PRNs are used to allow for the L1 C/A band to be shared between GPS, Galileo, Glonass, Compass, SBAS, ...Ground control segment talks to GPS satellites via dedicated frequencies.I found this memo from 2006 which mentions software bugs in older receivers -- PRN 32 is reported as the invalid PRN 0, which suggests something was storing it in a 5-bit field which can only fit 0..31:https://www.navcen.uscg.gov/pdf/gps/gpsnotices/50SW_GPSW_letter.pdfIt also mentions a military "Wide-Area GPS Enhancement" system which had a 30 PRN limit.
October 26, 2022US SSC delivers sixth GPS III satellite to Cape Canaveral, FloridaThe GPS III SV06, called Amelia Earhart, is slated to launch in January 2023.The US Space Force’s (USSF) sixth Global Positioning System (GPS) III satellite has been delivered to the Cape Canaveral Space Force Station, Florida, US.Known as Amelia Earhart, the GPS III Space Vehicle (SV)-06 was delivered by the Space Systems Command’s (SSC) Military Communication and Positioning, Navigation and Timing (PNT) Directorate.The shipping of Amelia Earhart from Lockheed Martin’s facility in Littleton, Colorado, to the Space Coast Regional Airport in Titusville, Florida, was supported by a C-17 Globemaster III military airlift aircraft.The aircraft was assigned under March Air Reserve Base, California-based 729th Airlift Squadron and supported the heavy lifting of SV06.
The USSF and Missile Systems Center deliver a GPS III satellite to Cape Canaveral Air Force Station, Florida. Credit: US Space Force/Los Angles Air Force Base.
NextSpaceFlight, updated November 14:Launch is January 18, 2023.
And a Falcon 9 from pad 40 will launch GPS III-6 for the U.S. Space Force on mid-January.
...NSF Threads for GPS III SV06 : Discussion...
A Falcon 9 from pad 40 will launch GPS III-6 for the U.S. Space Force on January 18 at 7 a.m. EST. Sunrise is 7:15 a.m.
Entering Stage Right, a Falcon 9 booster. http://nsf.live/spacecoast
081527Z JAN 23NAVAREA IV 50/23(11,26).WESTERN NORTH ATLANTIC.FLORIDA.1. HAZARDOUS OPERATIONS, ROCKET LAUNCHING 181200Z TO 181323Z JAN, ALTERNATE 191156Z TO 191319Z, 201152Z TO 201315Z, 211147Z TO 211310Z, 221143Z TO 221306Z, 231139Z TO 231302Z AND 241135Z TO 241258Z JAN IN AREAS BOUND BY: A. 28-36.11N 080-35.28W, 28-48.00N 080-17.00W, 28-45.00N 080-13.00W, 28-36.00N 080-23.00W, 28-30.88N 080-33.23W. B. 31-50.00N 077-00.00W, 31-54.00N 077-00.00W, 33-47.00N 075-24.00W, 34-02.00N 075-00.00W, 33-52.00N 074-26.00W, 33-30.00N 074-29.00W, 31-46.00N 076-57.00W.2. CANCEL THIS MSG 241358Z JAN 23.//
Departure! ASOG droneship is outbound to support the upcoming GPS III-6 mission - NET Jan 18nsf.live/spacecoast
GPSIII-SV06, encapsulated and set to launch next week on a Falcon 9.
142047Z JAN 23HYDROPAC 173/23(57,61).EASTERN SOUTH ATLANTIC.SOUTHWESTERN INDIAN OCEAN.SOUTH AFRICA.DNC 01, DNC 02.1. HAZARDOUS OPERATIONS, SPACE DEBRIS 1803Z TO 1933Z DAILY 18 THRU 24 JAN IN AREA BOUND BY 39-00.00S 017-00.00E, 47-00.00S 014-30.00E, 58-00.00S 043-00.00E, 50-30.00S 046-00.00E.2. CANCEL THIS MSG 242033Z JAN 23.
142047Z JAN 23HYDROLANT 123/23(57,61).EASTERN SOUTH ATLANTIC.SOUTHWESTERN INDIAN OCEAN.SOUTH AFRICA.DNC 01, DNC 02.1. HAZARDOUS OPERATIONS, SPACE DEBRIS 1803Z TO 1933Z DAILY 18 THRU 24 JAN IN AREA BOUND BY 39-00.00S 017-00.00E, 47-00.00S 014-30.00E, 58-00.00S 043-00.00E, 50-30.00S 046-00.00E.2. CANCEL THIS MSG 242033Z JAN 23.